Steam-boiler.



PATENTED'AUG. 23, 1904. G. HOK.

STEAM BOILER.

I APRLICATION FILED NOV. 17, 1903. 7 H0 MODEL. 2 SHEETS-SHEET'I.

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PATENTED AUG. 23, 1904.

- G. HOK.

STEAM BOILER.

APPLICATION FILED NOV. 17 1903.

2 SHEETS-SHEET 2.

ATTOQNEXS Patented August 23, 1904.

UNITED. STATES "PATENTI' OFF CE.

GUSTAF HOK, OF'ESKILSTUNA, SWEDEN.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 768,178, dated. August 23, 1904. Application filed November 17, 1903, Serial No. 181,541. (No model.)

To aZZ whom it may concern:

Be it known that LGUsTAF Host, a subject of the King of Sweden and Norway, residing at Eskilstuna, Sweden, have invented certain new and useful Improvements in and Relating to Steam-Boilers; and I do hereby declare the following to be a full, clear, and exact descrip tion of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form apart of this specification.

This invention relates to the construction and arrangement of that type of steam-boiler wherein groups of water-tubes forming the boiler proper are situated one above the other and wherein the tubes of the same group are placed onone and the same level.

The object of the invention is to cause the steam, which is generatedin the lower group of tubes to be conveyed through the tubes of the groups situated above without having to penetrate the Water contained in them. 'Thus the steam is conveyed to the steam-collecting drum or chamber in a much drier condition than has hitherto been the case.

The steam-boiler forming'the subject-mat ter of this application is illustrated by the accompanying drawings, in which- Figure 1 represents a longitudinal section of the boiler, Fig. 2 being a cross-section thereof along' the line C D of the preceding figure; and Fig. 3 is a similar view to Fig. 1, showing diagrammatically the courses taken by the steam and the water in flowing through the boiler.

(b a a are various groups of tubes, the latter being provided at their extremities with transverse headers 66 6 Between the various groups of tubes short tubes 0 and OZ connect alternately both ends and the centers of the groups with two headersthat is to say, as is represented best by Fig. 3, the connection between the ends is efiected by the short tubes 0?, and the connection between the central parts is obtained by the short tubes 0. Thus, as shown in Figs. 1 and 3, a serpentine-like passage -is formed, allowing the steam to be conveyed from the bottom to r the intense heat.

. fore be combined, as illustrated, with another with water.

instance in a is (see Fig. 3) allowed to pass into the header b and then fiows from the lefthand side through the tube d to the header 5, thence through the adjoining group of tubes (0 to the right-hand side of the header t, whence itpasses through the tube d to the header 6,- and so on to the steam-collector. Bythis arrangement a brisk generation of steam within each of the groups is promoted and the steam itself is conveyed on as soon as it reaches the surface of the water.

It is quite evident that a boiler of the kind just described must not be exposed to the hottest gases of combustion, because the parts if containing no water would suifer damage from Such a boiler A'must theretube-boiler B, entirely filled with water in the usual manner and placed underneath the. im-

proved boiler A and directly above the furnace, so that the lower boiler will absorb a considerablepart of heat produced by the gases of combustion before they come into contact with the improved boilerarranged at the top. The tubes of the lower boiler may be inclined and are of course completely filled Both the boilers communicate with one another. When-two such boilers are combined into one, the feed-water is supplied to the top one, whence it flows to that below. The difliculty which arises in this case depends on the fact that the ordinary boiler below must always be completely filled, while the horizontally-arranged tubes of the improved top boiler are only filled partially. If the supply of-water becomes eX- cessive, thesuperfluous water ascends to the topv boiler, thereby filling the above-mentioned horizontal tubes, whereas in the event of the supply not being suflicient the tubes of the lower boiler are not entirely filled with water, and both these possibilities must be considered as disadvantages. The improved combined tubular boiler cannot, therefore, be fed with water without a supply-regulating apparatus, and the latter must in consequence be included in the subject-matter of this specification. This Water-supply-regulating apparatus has for its object to prevent the steamspaces of the tubes of the top boiler from being entirely filled with water in case the supply becomes excessive and must be constructed in accordance with the position and size of the short tubes (Z. The bottom extremities of these tubes must reach slightly beyond the upper edge of the horizontal tubes (4 a (0 If the surface of the water inside the steam spaces reaches to the bottom edge of the short tube (Z, the steam-spaces in the horizontal tubes will be maintained, as the water closes the short tubes d. This closure hinders the steam from escaping from the horizontal tubes at a a and so prevents the tubes from being entirely filled with water. The steam, however, is in no way prevented from ascending, as the Water which effects the said closure allows the steam to pass. Its ascension, however, will not take place more quickly than it is generated, and the steam-space will there fore be maintained in the horizontal tubes. This arrangement prevents the horizontal tubes at a a from being entirely filled with water; but it also stops the steam from freely aseending and from becoming dry. This may be attained, however, by the following arrangement: The arrangement consists of avertical pipe d, divided into two parts by apartition 0', one part, 6, being in communication with the Water-receptacle, which is filled with water up to a certain level, while the other part, f, is connected by a short tube g with the lowest bottom group of tubes belonging to the upper boiler. The part f is provided with afloat it, connected by a lever arrangement with a valve '6 in the part a, the valve being placed in the top of a tube 7c, which leads to the uppermost group of tubes of the top boiler. The water in c assumes a level slightly higher than the top edge of the tube In, and the highest level of the water allowed in the part f assumes that of the upper edge of the lowest overflow-pipe of the top boiler. Both parts a and f of the pipe (Z therefore communicate at the top with the steam-collector. If the valve i is open, the feed-Water is allowed to run through the tube into the top boiler, whence it flows to the other. Thus both the boilers are supplied with Water. Should, however, the supply of water become excessive, the water in part f at once ascends, raising the float /1, whereby the lever arrangement causes the valve '2' to shut, and the water-sumfly to the boiler is automatically and instantaneously stopped. In the event of the supply not being suflicient the float a descends, thus again opening valve 2' and allowing a fresh supply of water to enter into part a of the pipe (2. If the float it does not work properly, the disadvantage is minimized because the level of water in the tubes may only reach, as has been explained, the bottom edge of the short tubes (Z, while the steam-spaces ol the horizontal tubes of the improved boiler are kept free-that is to say, the latter tubes are prevented from entirely filling with water. Hence the required proper supply of water for feeding the combined boilers is insured.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In a steam-generator, a lower group of tubes, an upper group of tubes and means for automatically keeping the lower group ol tubes full of water and the upper group only half full of water, substantially as described.

2. In a steam-generator, a lower group of tubes, an upper group of tubes, means for antomatically maintaining the lower group full of water and the upper group only half full, whereby a steam-space is formed in said upper group and means for connecting the steamspaces of the tubes of the group together, substantially as described.

3. In a steam-generator, a series of tubes horizontally arranged one above the other, headers connecting the ends of the tubes of each series, tubes 0 connecting the water-spaces of the headers and regulating the flow of water so that steam-spaces are formed in the tubes and means for connecting said spaces together, substantially as described.

4. In a steam-generator, series 0 t tubes horizontally arranged one above the other, headers connecting the ends of the tubes of each series together water-tubes connecting the headers of each series and arranged so as to keep the tubes half full of water and steam-tubes connecting the headers above the waterlevel therein, said tubes having their bottoms projecting under the highest water-level of the horizontal tubes.

In testimony that I claim the 'loregoing as my invention I have signed my name in presence of two subscribing witnesses.

GUS'IAF I 10K.

Vitnesses: V

Koun DA! 1 LoUIs'r, L. KALLENB nae. 

